N-Acetylmuramic acid

N-Acetylmuramic acid (NAM or MurNAc) is an organic compound with the chemical formula. It is a monomer of peptidoglycan in most bacterial cell walls, which is built from alternating units of N-acetylglucosamine (GlcNAc) and N-acetylmuramic acid, cross-linked by oligopeptides at the lactic acid residue of MurNAc.

Formation of NAM
NAM is an addition product of phosphoenolpyruvate and N-acetylglucosamine. This addition happens exclusively in the cell cytoplasm.

Clinical significance
N-Acetylmuramic acid (MurNAc) is part of the peptidoglycan polymer of bacterial cell walls. MurNAc is covalently linked to N-acetylglucosamine and may also be linked through the hydroxyl on carbon number 4 to the carbon of L-alanine. A pentapeptide composed of L-alanyl-D-isoglutaminyl-L-lysyl-D-alanyl-D-alanine is added to the MurNAc in the process of making the peptidoglycan strands of the cell wall.

Synthesis of NAM is inhibited by fosfomycin.

NAG and NAM cross-linking can be inhibited by antibiotics to inhibit pathogens from growing within the body. Therefore, both NAG and NAM are valuable polymers in medicinal research.